Saidemberg, Daniel M. [UNESP]Ferreira, Marco A. B.Takahashi, Tatiane N. [UNESP]Gomes, Paulo C. [UNESP]Cesar-Tognoli, Lilian M. M. [UNESP]da Silva-Filho, Luiz C. [UNESP]Tormena, Claudio F.da Silva, Gil V. J.Palma, Mario Sergio [UNESP]2014-05-202014-05-202009-11-01Toxicon. Oxford: Pergamon-Elsevier B.V. Ltd, v. 54, n. 6, p. 717-724, 2009.0041-0101http://hdl.handle.net/11449/19732Colonial spiders evolved a differential prey-capture behaviour in concert with their venom chemistry, which may be a source of novel drugs. Some highly active tetrahydro-beta-carboline (TH beta C) toxins were recently isolated from the venom of the colonial spider Parawixia bistriata; the spiders use these toxins as part of their chemical arsenal to kill and/or paralyze preys. The major TH beta C compound isolated from this venom was identified as 6-hydroxytrypargine, also known as PwTX-I. Most natural compounds of animal origin occur in low abundance, and the natural abundance of PwTX-I is insufficient for complete functional characterization. Thus, PwTx-I was synthesized using a Pictet-Spengler condensation strategy, and the stereoisomers of the synthetic toxin were separated by chiral chromatography. The fraction of venom containing a mixture of three natural TH beta C toxins and enantiomers of PwTx-I were analyzed for inhibition of monoamine oxidase (MAO)-A and -B and for toxicity to insects. We reveal that the mixture of the natural TH beta C toxins, as well as the enantiomers of PwTx-I, were non-competitive inhibitors of MAO-A and MAO-B and caused potent paralysis of honeybees. The (-)-PwTX-I enantiomer is 2-fold more potent than the (+)-PwTX-I enantiomer in the assays performed. (C) 2009 Elsevier Ltd. All rights reserved.717-724engSpider venomParawixiatoxinIndoylalkaloidChiral chromatographyMonoamine oxidaseArtigo10.1016/j.toxicon.2009.05.027WOS:000270626900002Acesso restrito2901888624506535